1. Field of the Invention
The present invention relates generally to a voltage stabilizing technology, and more particularly, to a fan-controlling system to control a plurality of fans with different pulse width modulation signals, so as to enable surge currents generated by the fans to occur at different time points when voltage levels of the PWM signals are changed, thereby preventing a voltage drooping effect from occurring.
2. Description of Related Art
With rapid development of the electronic industry, electronic products are developed to have multiple functions and high performance. In order to meet the package requirement for micromation of the electronic product, heat generated when an electronic component installed on a circuit board of an electronic product will be distinctly increased, the requirement for the fans in number is continually increased. For example, a 1U or 2U system comprises six to eight or even twelve fans. A conventional technology controls all of the fans with identical pulse width modulation (PWM) signals. As shown in FIG. 1, a signal generating module 10 generates a PWM signal, and the conventional technology controls fans 11, 12 with the PWM signal only.
In conjunction with FIGS. 2 and 3 for reference, when a PWM signal 100 generated by the signal generating module 10 is turned from low voltage level “0” into high voltage level “1”, the fans 11, 12 generate power (voltage or current) signals 301, 302 respectively. Due to load imposed by the fans 11, 12, a peak value of a total power signal 300 imposed on the fans 11,12 is increased instantly (as shown in FIG. 2), thereby affecting the power signal 200 too supply an electronic system having the fans 11, 12 too low a peak power 200a due to the load imposed by the fans 11, 12. Such the low peak power 200a can not supply the electronic system with sufficient operational power supply (OPS), making the electronic system can not work normally, and stability of the electronic system is also affected.
Accordingly, there exists a strong need in the art for a fan controlling system to solve various drawbacks of the above-described conventional technology.